So a little backstory to begin, 1999 Cherokee Classic Dessert Sand Paint mostly stock. I have done an OME 3.5 inch lift so sitting good. Slowly I have been upgrading the 18yr old components as time and money allow. My never ending issue is the gauges, I have the important ones such as Temp, Oil Pressure, Volts and Tach. However the luxuries of Speedo and Fuel Level seem to be elusive. Cruise control light comes on but with no speed will not work, the Airbag light Check Engine light both on and I have done a self diagnostic on the cluster, all good. New Fuel pump and 4 hole injectors, replaced VSS and both TSS, BTW the one at the back of the Transmission is a real SOB. New Clock Spring, New AC last summer, necessary here in FL. Next planned project is brakes and wheel bearings. But until the Gauge issue is handled I'm holding off


All this being said I have been thru many posts here and cannot find any answers. Any and all help would be greatly appreciated, I'm sure there is someone here who is much more knowledgeable than myself.


Thank you all in advance for any assistance.

 

The first easiest thing i'd do especially considering the cruise, airbag and CEL lights come on is pull the cluster, inspect the connectors for bent/spread pins.
By the way are there any CEL codes?

Did you change the clock spring because of these cluster gauge issues?
Bad install?

Take this with a grain of salt not batting a thousand here, but it seems like so far and its only a hunch at this point, the speedometer and fuel gauge issues are related to the cluster or possibly the clock spring?

Here's an old informative link by one of the master tech's for the VSS.
https://www.cherokeeforum.com/f2/spe...rt-2wd-198583/

 

The only code I get now is on the odometer self check, 25. I do not have an OBD reader. I've read up on it and says tps. I did originally change the clock spring because of the gauges. I used a Dorman replacement part with speed control. I did try a second cluster because the origami odometer was stuck there's as much as I know. I did use di-electrical grease when installing the 2nd cluster,

 

Code 25: Automatic Idle SPeed motor driver circuit. Short or open detected in one or more of the AIS control circuits.
How are you getting this code?
If its driveable take it to Auto Zone and get a complete CEL stored code readout or borrow a code reader.

I don't know about using the grease on the cluster connectors.
Not saying this is the problem but IMO i would not use dielectric grease on the cluster connectors. I could be wrong but i think they use gold plated contact pins to prevent corrosion.
The sensitive PCM bus signal is run through some of those connector contacts.

The airbag and CEL light on and cruise control issues seem to point to the clock spring. If its not installed right, it could cause all kinds of issues.
Does the engine start?

 

Engine starts and runs like a champ. 4wd high and low all work. Clockspring was pretty straight forward. Put everything back together same as it came out. Checked a couple of videos before doing it. The horn didn't work before replacing and now it does.

 

Got this code doing the key & trip button trick.

 

Could any of these be caused by a bad ground anywhere?

 

Yeah OK but you indicated it was an odometer #25 failure.
Anyway on to bigger and better things.

Don't ignore the real #25 CEL code.
It pertains to the Idle Air Control (IAC) located on the throttle body, its connector or wiring.
Check the IAC connector for corrosion or bent/spread pins.
Also check the wiring to it for shorts or opens.
Or the IAC stepper motor could be shot then the IAC needs replacement.

Did you replace or clean the IAC?
Remove it and clean it, thats all that might be wrong.
Plenty of Utube videos on how to clean it.

Any of those IAC issues could corrupt the PCM bus and cause weird problems like you're experiencing.
Your really need to get an OBD-2 CEL trouble code analysis for any stored codes.

 

So I got ahold of an OBD scanner and get code P0505. Checking it online I get IAC problem. Going to grab my volt meter from the office and check it all out. Probably just replace.

 

Yeah, CEL codes 25 and 505 pertain to something going on with the IAC.
CEL code 25 suggests an open or short detected and 505 suggest an IAC malfunction.

Before replacing it, check all cable harnesses for any signs of wear which could cause a short or open circuit wire in harness.
It could also be a short or open in the IAC motor coil.

After checking the harnesses, i would pull the IAC and clean it first before replacing, Mopar's IACs are relatively expensive.
It could be binding from debris causing the motor to stall which i believe the PCM can detect then sets the CEL codes and who knows what else.

If you do replace it or find/fix a harness problem, make sure you clear those CEL Codes with the OBD-2 scanner.

 

I'm not a 100% sure about your 99 but I know on older models there is a ground for the instrument panel (and other things too I think) on a dash support bar under the dash to the left of the steering column, on my 93 it worked well to remove the lower portion of the dash, I'm not entirely sure how the 99 dash works so this might not help, and then I could see it easily. It's a pretty poor design for a ground point so clean it up nicely and see it that fixes the gauges.

 

you could also try pulling the instrument cluster and tightening the little ground screws on the back of it